Back to results
US 5,686,806 AGranted
Low-pass filter and electronic speed control system for electric motors
AssigneeTrans-Coil, Inc.
InventorJohn F. Hibbard
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeTrans-Coil, Inc.
InventorJohn F. Hibbard
Estimating the term…
A three-phase, low-pass filter for use in an electronic speed control system and wherein an adjustable speed drive is disposed in signal transmitting relation relative to an electric motor by an electrical conduit having a predetermined length, and wherein each single-phase circuit of the three-phase, low-pass filter includes an inductor having input and output nodes, a first resistor electrically coupled in parallel to the inductor, a second resistor having input and output nodes, and wherein the input node of the second resistor is electrically coupled to the output node of the inductor, and a capacitor having input and output nodes, and wherein the input node of the capacitor is electrically coupled to the output node of the second resistor, and wherein the low-pass filter is electrically coupled to the electrical conduit and operable to substantially filter out frequencies that tend to excite the natural resonant frequency of the electrical conduit.
An electronic speed control system including an adjustable speed drive that has an inverter for producing a voltage waveform, the adjustable speed drive disposed in signal transmitting relation to an electric motor by an electrical conductor having a sufficient length so that the resonant frequency of the conductor is at, or below, high frequency components of the voltage waveform, and a low-pass filter, and wherein the low-pass filter comprises:
A low-pass filter for use in an electronic speed control system which includes an adjustable speed drive that has an inverter, the adjustable speed drive electrically coupled to an AC motor by one or more electrical conductors each having a length of at least 50 feet, and a resonant frequency that is at, or below, high frequency components of the output of the inverter, the low-pass filter comprising:
A three-phase, low-pass filter for use in a three-phase electronic speed control system which includes an adjustable speed drive that has an inverter, the adjustable speed drive disposed in signal transmitting relation to an electric motor by one or more electrical conductors each having a sufficient length so that the resonant frequency of each of the conductors is at, or below, high frequency components of the output of the inverter, and wherein each single-phase circuit of the three-phase, low-pass, filter comprises:
An electronic speed control system including an adjustable speed drive that has an inverter for producing a voltage waveform, the adjustable speed drive disposed in signal transmitting relation to an electric motor by an electrical conductor having a sufficient length so that the resonant frequency of the conductor is at, or below, high frequency components of the voltage waveform, and a low-pass filter, and wherein the low-pass filter comprises:
Dependencies are inferred from the claim text.